FILE - Jan. 12, 2016 file photo, New York City Police Commissioner William Bratton, left, speaks during a news conference in New York's City Hall, as New York Mayor Bill de Blasio listens. (AP Photo/Richard Drew, File)

Related Headlines

NEW YORK (FOX 5 NY) - Bill Bratton, the commissioner of the New York City Police Department, will retire in mid-September, Mayor Bill de Blasio announced at a news conference Tuesday.

Chief of Department James O'Neill will replace Bratton, who is leaving for a job in the private sector.

"I wish I had words for what this man has achieved. One thing that doesn't get talked about Bill Bratton is his heart. He's been an extraordinary partner. It is a beautiful thing when you can once again make a city better and safer," said de Blasio.

"I have many people to thank. Mr. Mayor, thank you for all that you do. The Mayor allowed me to come back to the city that I love. It is now time for me to move on. This city and this department will have a seamless transition," said Bratton.

On July 25, Bratton, 68, had said he would not remain commissioner of the department past 2017. The announcement of a resignation was not anticipated this soon.

"I informed him that I would be retiring in mid-September to pursue other opportunities," said Bratton.

During the announcement from City Hall, de Blasio said he would "deeply miss" Bratton after working together for the past 31 months.

O'Neill, a native New Yorker from Brooklyn, is "the real deal," said de Blasio.

"It's been an amazing 16 hours. Never in my life, when I came on the force in 1983 did I think I would be here at the podium as police commissioner. I love being a cop. I love this uniform and everything it stands for," said O'Neill.

Bratton's resignation comes as members of the largest police union protested outside Mayor Bill de Blasio's Gracie Mansion home and the YMCA in Park Slope, Brooklyn Tuesday morning.

The frustrated police officers say they plan to continuing protesting over the next several weeks. They cite Hizzoner's failed leadership, poor relationship with the NYPD and refusal to reach a so-called market rate of pay with cops.

About a dozen cops shouted "one term mayor" as de Blasio walked into the gym.

In May, the Sergeants Benevolent Association called for Bratton's immediate resignation saying: "It's time that we start to set the department straight, and if we need to make changes at the top, I personally think Bratton has stayed too long, and it's time to go."

At least nine high ranking individuals are under investigation for corruption.

The mayor said Bratton's resignation had "110 percent" nothing to do with the federal corruption probe of City Hall.

This was Bratton's second run as NYPD Commissioner. He served under Mayor Rudy Giuliani from January 1994 to April 1996.